The present invention relates to an enzymatic treatment for wood chips or wood pulps which enhances fibrillation and facilitates delignification and bleaching.
Previous enzymatic and biopulping processes do not take into account the presence of extensin in cell walls. Extensin is a highly crosslinked protein, rich in proline and hydroxyproline which is not affected by xylanases and peroxidases such as ligninases. It is hypothesized that lignin is bound to extensin and functions as a supporting skeleton for cells. Extensin or lignin is most likely immobilized in cell walls during formation of the secondary wall.
Partial degradation of extensin would, therefore, appear to be important in making the lignin more accessible for extraction in chemical pulping and bleaching or to reduce energy consumption and damage to cellulose fibers during mechanical pulping.